Perhaps the first time was modifying MySpace or some 90s/2000s social media site.
It's used for laying out pages, adding buttons or building whole UIs. Safari, Chrome, Firefox, Edge, Opera all implement some latest standard of HTML.
What's your biggest issue with HTML today in 2022? What's the one big thing you would change? Which of your needs are not being met with HTML as it is today?
But the big issue is all the UI stuff that goes around that editorial content, that we have to reinvent all the time or use piles of third-party stuff for. HTML has no tabs, no cards, no popins, no mega menus, no button groups, no steppers, etc.
We shouldn't use that "platform" to build applications.
God, I wish we just had a better language for the Web altogether. Something with sane UI primitives that automatically translate into platform API calls (i.e. you say
Lack of widgets. We have people writing emoji pickers in JS and placing them in documents, and some of them work horribly on mobile. Then there's the caveat of emoji pickers being already available on mobile and no such JS widget is needed. Then there's 100+ variations of dropdown menus implemented in JS, which all have their own bugs, don't work well on mobile, and are already somewhat natively available on mobile anyway so the JS widget is not needed.
When people claim they want HTML improved I stop taking them seriously.